Pistols and revolvers are examples of handguns. A cartridge is a combination of a bullet and a shell, wherein the shell contains the gunpowder that upon exploding within the firing chamber of a handgun blows the bullet as a projectile out through the barrel of the handgun.
In the example of pistols, the firing chamber is generally integral with the barrel and usually a linear magazine within the handle grip of the pistol sequentially feeds a series of cartridges to the firing chamber. In the example of revolvers, a rotatable cylinder with a series of circumferentially distributed firing chambers align sequentially a series of cartridges with the revolver's barrel.